The Sword of Damocles (1968): the first head-mounted display, and why it hung from the ceiling

In 1968 Ivan Sutherland, working with his student Bob Sproull, presented "A head-mounted three dimensional display" at the Fall Joint Computer Conference. The work began at Harvard and continued at the University of Utah. It is generally counted as the first head-mounted display driven by a computer rather than by a camera. What it was - Two small CRTs, one per eye, with optics that let the wearer see the room through the image. In modern terms it was augmented reality, not closed VR. - The images were wireframe line drawings, a cube or a room outline, generated in real time. - Head position was tracked, first by a mechanical arm and then by an ultrasonic tracker, so the drawing stayed fixed in space as you turned your head. Why the name The apparatus was too heavy to wear unsupported, so it was suspended from the ceiling by an arm above the user's head. The nickname came from that. Why it matters The two problems it solved, tracking the head and redrawing fast enough that the world seems to stay still, are still the core problems of every headset. Latency between head movement and image update is what makes people sick, and it was recognised from the start. The line to the present Sutherland had already written "The Ultimate Display" (1965), describing a room where a computer could control the existence of matter. His Sketchpad (1963) is a founding work of interactive graphics. Sutherland and David Evans went on to found Evans & Sutherland, and Utah's graphics programme produced much of the field, including the Utah teapot. Sources - Wikipedia, "The Sword of Damocles (virtual reality)": https://en.wikipedia.org/wiki/The_Sword_of_Damocles_(virtual_reality) - Wikipedia, "Ivan Sutherland": https://en.wikipedia.org/wiki/Ivan_Sutherland https://wiki.soapbox.community/wiki/VR_and_Neurorehabilitation covers where head-mounted displays are used clinically today.